I saw something yesterday I've never seen before. I was at ORD waiting for upgrades to be processed for my UAX flight. The list was 8 people long, with 3 seats available.

The GA called the first person on the list (call him Mr. A) to come to the desk. After a few seconds he tried again. With no sign of Mr. A, the GA called up Mr. B. This process continued until Mr. B, Mr. D, and Mr. E had been upgraded and Mr. A and Mr. C were not.

I have no idea why this happened, but I now feel less guilty about hovering by the gate if I think I have a chance for an upgrade.